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Folate Vs Folic Acid: Which Vitamin B9 Should You Pick?

Folate Vs Folic Acid

Folate and folic acid are natural and synthetic forms, respectively, of vitamin B9. You get folate through natural foods like leafy greens and nuts and folic acid from supplements or fortified food grains. Unless you have a chronic deficiency or a special need, like during pregnancy, get your folate solely from food. Whereas folate protects against cancer, excess folic acid is linked to increased cancer risk.

Let’s suppose you have just decided to get pregnant. You know that you need to increase the intake of all nutrients, especially essential ones like folate or folic acid. But which of these should you take? Are folate and folic acid the same thing? Or are they different? The answer is that they are different – and yet, they aren’t! In the family of the 8 B vitamins, vitamin B9 is referred to as folate or folic acid. In that sense, folate and folic acid are the same, referring to the same nutrient. However, their chemical structures are different, and that leads to several differences which you need to consider to determine which form of vitamin B9 you should choose.

1. Folate Occurs In Unprocessed Food; Folic Acid Is Found In Supplements

Folate is found naturally in foods such as green leafy vegetables, fruits, and seeds. Here’s a list:

  • Green, leafy vegetables: Asparagus, broccoli, Brussels sprouts, mustard greens, romaine lettuce, spinach, turnip greens
  • Beans: Garbanzo beans, kidney beans, lima beans, mung beans, soybeans, white beans
  • Vegetables: Beet, carrots, cauliflower, celery, corn, okra, peas, root vegetables, squash, tomato, turnip
  • Grains: Whole grains, bulgur wheat, wheat germ
  • Fruits: Avocado, banana, cantaloupe, grapefruit, oranges, papaya, raspberries, strawberries
  • Seafood: Halibut, Dungeness crab, salmon
  • Nuts and seeds: Almonds, flax seeds, peanuts, sunflower seeds
  • Dairy: Milk, cheese, yogurt
  • Meats: Chicken, beef, liver1

Folic acid, on the other hand, does not exist naturally and is the synthetic version of vitamin B9. It is a highly oxidized and stable compound. You may also hear folate referred to as folacin – but don’t let that fox you!2

Folic acid is prescribed as a supplement for managing various conditions. As a supplement, you will find it in multivitamins and prenatal vitamins. It is also available in B-complex dietary supplements or sold under its own name.

Folic acid is also used to fortify several widely consumed foods like bread, flour, cold breakfast cereals, and energy bars.3 4 Since 1998, grains and cereals sold in the U.S. are all usually fortified with folic acid to prevent folate deficiency in early pregnancy (when the pregnancy itself might be undetectable), which leads to neural tube defects in the newborn. To find out whether a grain-based product has been fortified with folic acid, read the label.5

2. Food Folate Is Less Bioavailable Than Folic Acid

Although both folate and folic acid are two forms of vitamin B9, they are not equal in terms of bioavailability – bioavailabilty refers to the amount of usable form of folate available to the body for various functions.

It has long been considered that the bioavailability of food folate is less than that of folic acid from supplements.

The recommended daily intake of folate is measured by DFE, which stands for dietary equivalent of folate. Since folic acid is more bioavailable than food folate,  1 DFE = 1 mcg food folate = 0.6 mcg folic acid from supplements and fortified foods.

Different studies have found different degrees of bioavailability of food folates, ranging from 30% to 98%, depending on the food matrix or the composition of the foods eaten.6 7 Though the NIH now pegs the bioavailability of food folate at 60% of folic acid when taken with food (either as fortified foods or supplements), consuming a mixed diet that includes foods rich in folate can be just as effective as taking folic acid supplements.8 9

3. Folic Acid Is Not Readily Usable; Some Food Folates May Be

Both folate from natural food and folic acid from supplements and fortified foods must be transformed into L-methylfolate, the form that the body can absorb and use. While some natural foods like green leafy veggies and sprouts may contain higher levels of L-methylfolate – eat them raw or steamed – folic acid always needs to be converted to folate first.

To convert folic acid from supplements or fortified food to an usable form in the body, 2 enzymes are required. DHFR converts folic acid to folate, and MTHFR converts folate to L-methylfolate. L-methylfolate is the usable, functional form of folate.

There’s an extra step in the conversion of folic acid into the usable form. So while folate is processed in the small intestine and transformed to L-methylfolate, folic acid is first processed in the liver and converted to folate.10

This difference is critical. Since the conversion of folic acid to folate depends on an enzyme called DHFR, if you are deficient in the enzyme or you have taken in more folic acid than the enzyme can convert, there will be excess unmetabolized folic acid left in circulation. This can affect your health adversely. But even with a DHFR deficiency, you can get sufficient folate from natural sources.

4. Excess Folic Acid Can Cause Health Problems; Folate Does Not

Unmetabolized folic acid in the blood plasma can sometimes create some of the following health problems, which can be averted if you get your folate from food.

  • Mask deficiency of vitamin B12: Experts say that too much folic acid may mask symptoms of anemia, which is an early sign of vitamin B12 deficiency. B12 is essential for maintaining nerve health and a deficiency could result in confusion, dementia, and even permanent damage to the nerves, spinal cord, and brain. Vitamins B9 and B12 usually work in tandem to help in the formation of red blood cells and, together, they can help fight anemia. This is why the reduced availability of vitamin B12 may often go unnoticed.11 Vitamin B12 deficiency is common among older people with reduced stomach acid, strict vegetarians and vegans, and people who have used antacids or proton pump inhibitors for a long time.12
  • Promote growth of cancer cells: Recent research shows that too much folic acid in our bodies can block the entry of natural folate into the cells.13 While folate and folic acid can fight cancer cells when consumed within a limit, this equation flips when folic acid supplementation is too high. How? That takes us to the next point.
  • May affect immune function: In one study, circulating folic acid was found to decrease the efficiency of natural killer (NK) cells. These cells are part of our immune system and can kill many types of normal and virus-infected cells, including tumor cells. While this finding needs to be corroborated with larger studies,14 it is one possible reason excess folic acid increases cancer risk.

5. Folate Lowers Cancer Risk; Excess Folic Acid Can Raise The Risk

Studies show that folate-rich foods could reduce the chances of colorectal cancer, pancreatic cancer, and esophageal cancer. Such a diet may also reduce the risks of breast cancer after menopause, especially among women who have a family history of breast cancer. Other cancers, such as those of the stomach, prostate, ovaries, and lungs, do not appear to be affected either way by a folate-rich diet.15

Since alcohol in the blood hinders the absorption of folate, women who drink 1.5–2 alcoholic drinks a day are more vulnerable to breast cancer. But increasing dietary folate, not folic acid, can reduce this risk.16

Although it is not understood how exactly folate prevents cancer, it is believed to promote DNA health and prevent mutations that could lead to cancer. It is also believed that a person consuming a folate-rich diet is consuming a healthy diet – natural sources of folate are also high in the other essential nutrients – and that is what is lowering the risk of cancer.17

Large amounts of folic acid may accelerate the transformation of any existing abnormal tissues to cancer. Cancer cells require more nourishment than normal cells as they rapidly multiply. In other words, a tumor needs folate to keep growing. Thus, for people who have cancer or have been detected with precancerous growths, folic acid supplements could prove to be detrimental. On top of that, excess unmetabolized folic acid can affect the immune system’s ability to kill tumor cells. Food folate in recommended dietary amounts, however, does not increase the risk.18

6. Folate Protects Against Heart Diseases; Folic Acid May Not

Since the levels of homocysteine in blood increase with age, older adults must get 400 mcg folate from a multivitamin supplement as well as folate-rich foods.19

A diet rich in folate is associated with a lowered risk of cardiovascular disease (CVD), including stroke, coronary artery disease, and heart attack.20 Folate works together with vitamins B6 and B12 to regulate levels of homocysteine, an amino acid present in our blood. High levels of homocysteine are believed to be connected with heart disease, although the exact connection is still not very clear.21

Though folic acid supplements also reduce homocysteine levels, it is not clear whether CVD risks are similarly lowered. In fact, tests show that the expected reduction in CVD risks does not happen with folic acid in spite of lowered blood homocysteine levels.22

Choose Folate Over Folic Acid Unless Chronically Deficient

Up to 60% of Americans have a genetic condition where the MTHFR enzyme that converts folate into its usable form does not function optimally. This causes folate deficiency.23 Folic acid supplementation will not help, but foods with high levels of L-methylfolate (green leafy veggies and sprouts) and direct L-methylfolate supplementation can certainly help.

Undoubtedly, folate from dietary sources should be the form of vitamin B9 you ought to choose, but you may need to depend on folic acid when there is a shortfall. This is what the Dietary Guidelines for Americans also recommends.24

Folate deficiency is uncommon but can be caused when you cannot absorb adequate amounts due to aging, excessive alcohol consumption, smoking, ailments like inflammatory bowel disease and celiac disease, and gene mutations like MTHFR mutation.

You would also need extra folate during pregnancy to avoid birth defects. It has been seen that folic acid supplementation during pregnancy, on top of dietary folate, can prevent birth defects like spina bifida and anencephaly, cleft lips, autism and delay in developing language skills by 3 years of age, and emotional problems in babies.25 26 27 Researchers now suggest that L-methyfolate supplementation may be even more effective, particularly if the mother has an MTHFR mutation, though further research is required to establish this use.28

The Dosage Of Folic Acid You Need

The recommended daily dietary allowance for folic acid supplements as per age:

  • 1–13 years: 150 mcg–300 mcg DFE
  • 14–19 years and above: About 400 mcg DFE
  • Pregnant women or women planning to conceive: 600 mcg DFE (neural tube defects in the fetus can develop in the early days after conception or even before pregnancy is confirmed)29
  • Breastfeeding mothers: 500 mcg DFE30

Remember, though, taking over 1000 mcg folic acid per day over a long period can tip the balance and lead to symptoms like irritability or intestinal malfunctions, not to mention the possible effects of unmetabolized folic acid we already mentioned.31

Symptoms Of Folate Deficiency

  • Reduced appetite
  • Poor growth
  • Gingivitis
  • Diarrhea
  • Memory loss
  • Mental dullness
  • Irritability
  • Inflammation of the tongue
  • Changes in skin, hair or fingernail color
  • Heart palpitations
  • Megaloblastic anemia, symptoms of which include shortness of breath, fatigue, and weakness32 33 34

Be Careful: Folic Acid Can Interfere With Other Medication

Though you may be taking folic acid well within the recommended dosage, be aware that folic acid can sometimes interfere with the efficacy of certain prescribed medications – for instance, antibiotics such as tetracycline. Conversely, the presence of certain medications in the blood, such as antacids or non-steroidal anti-inflammatory drugs, can affect the absorption of folate. Speak to your doctor or pharmacist to find out if folic acid will interfere with your existing medications or vice versa.

In conclusion: Folate from natural foods promises better health than folic acid. But since folate is less bioavailable than folic acid, in cases of deficiencies or during pregnancy, a folic acid supplementation may be recommended. Within the recommended limit, folic acid is not harmful, but it can create several health problems if taken in excess. To avert these health risks, preliminary research now points toward supplementation with L-methylfolate, the form of folate that can be readily used in the body.

References   [ + ]

1, 3, 16, 17, 21, 27, 33. Vitamin B9 (Folic acid). University of Maryland Medical Center.
2, 19. Folate. Oregon State University.
4. Three Of The B Vitamins. Harvard T. H. Chan School Of Public Health.
5. Folate. NIH.
6. Ohrvik, Veronica E., and Cornelia M. Witthoft. “Human folate bioavailability.” Nutrients 3, no. 4 (2011): 475-490.
7. Powers, Hilary J. “Folic acid under scrutiny.” British Journal of Nutrition 98, no. 4 (2007): 665-666.
8. Caudill, Marie A. “Folate bioavailability: implications for establishing dietary recommendations and optimizing status–.” The American journal of clinical nutrition 91, no. 5 (2010): 1455S-1460S.
9. Folate. NIH.
10. Folic acid and folate in foods. Harvard Health Publications.
11, 30, 31, 34. Folate. NIH.
12, 13. Folic acid: Too much of a good thing?. Harvard Health Publications.
14. Troen, Aron M., Breeana Mitchell, Bess Sorensen, Mark H. Wener, Abbey Johnston, Brent Wood, Jacob Selhub et al. “Unmetabolized folic acid in plasma is associated with reduced natural killer cell cytotoxicity among postmenopausal women.” The Journal of nutrition 136, no. 1 (2006): 189-194.
15. Folate and Cancer Risk – Position Statement. Cancer Council NSW.
18. Three Of The B Vitamins. Harvard T. H. Chan School Of Public Health.
20, 22. Folate. Oregon State University (OSU).
23, 28. Greenberg, James A., Stacey J. Bell, Yong Guan, and Yan-hong Yu. “Folic acid supplementation and pregnancy: more than just neural tube defect prevention.” Reviews in Obstetrics and Gynecology 4, no. 2 (2011): 52.
24. Folate. NIH.
25. Czeizel, Andrew E., and István Dudás. “Prevention of the first occurrence of neural-tube defects by periconceptional vitamin supplementation.” New England Journal of Medicine 327, no. 26 (1992): 1832-1835.
26. Wilcox, Allen J., Rolv Terje Lie, Kari Solvoll, Jack Taylor, D. Robert McConnaughey, Frank Åbyholm, Hallvard Vindenes, Stein Emil Vollset, and Christian A. Drevon. “Folic acid supplements and risk of facial clefts: national population based case-control study.” Bmj 334, no. 7591 (2007): 464.
29, 32. Folate. Oregon State University.

Disclaimer: The content is purely informative and educational in nature and should not be construed as medical advice. Please use the content only in consultation with an appropriate certified medical or healthcare professional.